A MANHOLE COVER ON TRUCK SCALE HAD A CORRODED SUPPORT BLOCK WHICH GAVE AS EE WALKED ON IT. EMPLOYEE FELL, HIT HIS KNEE AND SCRAPED HIS SHINS AND CAUGHT HIMSELF WITH HIS HANDS. THIS RESULTED IN MINOR CONTUSTIONS/SCRAPES. DR. PRESCRIBED CELEBREX & VICODIN AND EMPLOYEE WAS PUT ON MODIFIED DUTY. FOLLOW UP ON 7/19/2004, DR ORDERED EE OFF FROM WORK.